Prefillable intradermal delivery device

ABSTRACT

An intradermal delivery device for use in intradermally injecting substances into the skin of an animal includes a needle cannula supported by a hub portion that is attachable to a prefillable container. A limiter portion surrounds the needle cannula and extends away from the hub portion toward a forward tip of the needle cannula. The limiter portion includes a skin engaging surface extending in a plane generally perpendicular to an axis of the needle cannula. The skin engaging surface is received against skin of an animal to administer an intradermal injection. The forward tip extends beyond the skin engaging surface a distance that enables penetration of the needle cannula into the dermis layer of the skin of the animal enabling injection of the substance into the dermis layer of the animal. The device includes enclosure means that is moveable for concealing the needle cannula after the injection has been administered.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.09/835,248, filed on Apr. 13, 2001, now U.S. Pat. No. 6,776,776, whichis a continuation-in-part of U.S. patent application Ser. No. 09/417,671filed on Oct. 14, 1999, now U.S. Pat. No. 6,494,865.

FIELD OF THE INVENTION

The present invention relates generally to delivery devices fordelivering substances such as drugs, vaccines and the like, and morespecifically relates to a drug delivery device having a needle cannulaand a limiter for engaging the surface of the skin and limitingpenetration of the tip of the needle cannula into the skin. Morespecifically, the present invention relates to a limiter capable offixing the orientation of the needle cannula in a generallyperpendicular plane to the skin engaging surface of the limiter andcapable of enclosing the needle cannula subsequent to administering theintradermal injection.

BACKGROUND OF THE INVENTION

Intradermal injections are used for delivering a variety of substances.Many of these substances have proven to be more effectively absorbedinto or react with the immune response system of the body when injectedintradermally. Recently, clinical trials have shown that hepatitis Bvaccines administered intradermally are more immunogenic if administeredintramuscularly. In addition, substances have been injectedintradermally for diagnostic testing, such as, for example using what isknown in the art as the “Mantoux test” to determine the immunity statusof the animal against tuberculosis and the immediate hypersensitivitystatus of Type I allergic diseases.

An intradermal injection is made by delivering the substance into theepidermis and upper layers of the dermis. Below the dermis layer issubcutaneous tissue (also sometimes referred to as the hypodermis layer)and muscle tissue, in that order. There is considerable variation in theskin thickness both between individuals and within the same individualat different sites of the body. Generally, the outer skin layer,epidermis, has a thickness between 50–200 microns, and the dermis, theinner and thicker layer of the skin, has a thickness between 1.5–3.5 mm.Therefore, a needle cannula that penetrates the skin deeper than about3.0 mm has a potential of passing through the dermis layer of the skinand making the injection into the subcutaneous region, which may resultin an insufficient immune response, especially where the substance to bedelivered intradermally has not been indicated for subcutaneousinjection. Also, the needle cannula may penetrate the skin at tooshallow a depth to deliver the substance and result in what is commonlyknown in the art as a “wet injection” because of reflux of the substancefrom the injection site.

The standard procedure for making an intradermal injection is known tobe difficult to perform, and therefore dependent upon experience andtechnique of the healthcare worker. This procedure is recommended to beperformed by stretching the skin, orienting the bevel of a 26 Gaugeshort bevel needle cannula upwardly and inserting the needle cannula todeliver a volume of 0.5 ml or less of the substance into the skin of ananimal with the needle cannula being inserted into the skin at an anglevarying from around 10–15 degrees relative to the plane of the skin toform a blister or wheal in which the substance is deposited or otherwisecontained. Accordingly, the technique utilized to perform the standardintradermal injection is difficult and requires the attention of atrained nurse or medical doctor. This procedure also makes itessentially impossible to self-administer an intradermal injection.Inserting the needle to a depth greater than about 3.0 mm typicallyresults in a failed intradermal injection because the substance beingexpelled through the cannula will be injected into the subcutaneoustissue of the animal. Further, the standard method is not suitable forself-administration of intradermal injections.

Further, with the advent of viral infections that are transferredthrough contact with bodily fluids, it is desirable to enclose orconceal a needle cannula subsequent to administering an injection.Preferably, a delivery device should include a mechanism that is capableof enclosing a needle cannula immediately subsequent to administeringthe injection. If a needle is left uncovered for even a short period oftime after administering an injection, such as, for example, whiletrying to reattach a needle cap, a biohazard exists. Therefore, it isdesirable to provide an intradermal delivery device with a means forenclosing the needle cannula that is simply designed, easy to use, andreadily available immediately after administering an injection.

Accordingly, there has been a need for a delivery device providing theability of performing an intradermal injection of substances whichovercomes the problems and limitations associated with conventionaldevices which may also be self-administered. Further, there has been aneed to provide the delivery device with the ability to enclose a needlecannula immediately subsequent to administering the intradermalinjection. The combination of these two features in the same deliverydevice would provide the ability to both reduce the probability of errorand pain caused from the intradermal injection and to conceal the needlecannula after the injection has been administered.

SUMMARY OF THE INVENTION AND ADVANTAGES

In contrast to the devices discussed above, the present invention bothenables the administration of an intradermal injection utilizing asimplified method that reduces the probability of error and also enablesthe user to enclose the needle immediately after administering theinjection.

An intradermal delivery device for use in intradermally injectingsubstances into the skin of an animal includes a prefillable reservoiradapted to contain the substance. An outlet port is in fluidcommunication with the reservoir. A needle cannula is in fluidcommunication with the outlet port and includes a forward tip extendingaway from the delivery device. The forward tip is adapted forpenetrating the skin of an animal. A limiter portion surrounds theneedle cannula and includes a generally flat skin engaging surfaceextending in a plane generally perpendicular to an axis of the needlecannula. A hub portion is secured around the needle cannula and definesa locator for the limiter to position the limiter upon the device. Theskin engaging surface is adapted to be placed against skin of an animalto administer an intradermal injection of the substance. The forward tipof the cannula extends beyond the skin engaging surface a distance equalto approximately 0.5 mm to 3 mm such that the limiter limits penetrationof the needle cannula to the dermis layer of the skin of the animalthereby enabling injection of the substance into the dermis layer of theanimal. An enclosure means encloses the needle cannula following theintradermal injection.

The present invention provides the desirable features set forth abovethat are not presently included together on the same needle assembly.The limiter allows an intradermal injection to be made at a generallyperpendicular angle to the angle to the skin of the animal and then alsoencloses the needle subsequent to administering the injection.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of the intradermal delivery device of thepresent invention;

FIG. 2 is a side sectional view of the intradermal delivery device ofthe present invention showing a hypodermic needle assembly;

FIG. 3A is an exploded view of the inventive limiter and hub;

FIG. 3B is a perspective view of an alternative skin engaging surface;

FIG. 4 is a side sectional view of the needle assembly showing theforward tip exposed for administering an intradermal injection;

FIG. 5 is a side sectional view of the needle assembly showing theforward tip retracted into the limiter to conceal the needle cannula;

FIG. 6 is a side sectional view of an alternative embodiment of theneedle assembly showing the forward tip exposed for administering anintradermal injection; and

FIG. 7 is a side sectional view of the alternative embodiment of theneedle assembly showing the forward tip retracted into the limiter toconceal the needle cannula;

FIG. 8A is a side sectional view of an alternative embodiment of theneedle assembly showing the inventive sleeve.

FIG. 8B is a side sectional view of the inventive sleeve enclosing theneedle cannula.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2, an intradermal delivery device for injectingsubstances into the skin of an animal is generally shown at 10. Thedevice includes a prefillable container 12 having a reservoir 14 forstoring substances intended for injection into the skin of an animal.These substances include vaccines and certain medicaments and drugs.Additionally, these substances can be used for diagnostic testing suchas, for example, the Mantoux test to determine immunity status againsttuberculosis and immediate hypersensitivity status of Type I allergicdiseases.

Also, the substance intradermally delivered in accordance with themethod of the present invention is selected from the group consisting ofdrugs, vaccines and the like used in the prevention, diagnosis,alleviation, treatment, or cure of disease, with the drugs includingAlpha-1 anti-trypsin, Anti-Angiogenesis agents, Antisense, butorphanol,Calcitonin and analogs, Ceredase, COX-II inhibitors, dermatologicalagents, dihydroergotamine, Dopamine agonists and antagonists,Enkephalins and other opioid peptides, Epidermal growth factors,Erythropoietin and analogs, Follicle stimulating hormone, G-CSF,Glucagon, GM-CSF, granisetron, Growth hormone and analogs (includinggrowth hormone releasing hormone), Growth hormone antagonists, Hirudinand Hirudin analogs such as hirulog, IgE suppressors, Insulin,insulinotropin and analogs, Insulin-like growth factors, Interferons,Interleukins, Leutenizing hormone, Leutenizing hormone releasing hormoneand analogs, Low molecular weight heparin, M-CSF, metoclopramide,Midazolam, Monoclonal antibodies, Narcotic analgesics, nicotine,Non-steroid anti-inflammatory agents, Oligosaccharides, ondansetron,Parathyroid hormone and analogs, Parathyroid hormone antagonists,Prostaglandin antagonists, Prostaglandins, Recombinant solublereceptors, scopolamine, Serotonin agonists and antagonists, Sildenafil,Terbutaline, Thrombolytics, Tissue plasminogen activators, TNF-, andTNF-antagonist, the vaccines, with or without carriers/adjuvants,including prophylactics and therapeutic antigens (including but notlimited to subunit protein, peptide and polysaccharide, polysaccharideconjugates, toxoids, genetic based vaccines, live attenuated,reassortant, inactivated, whole cells, viral and bacterial vectors) inconnection with, addiction, arthritis, cholera, cocaine addiction,diphtheria, tetanus, HIB, Lyme disease, meningococcus, measles, mumps,rubella, varicella, yellow fever, Respiratory syncytial virus, tickborne japanese encephalitis, pneumococcus, streptococcus, typhoid,influenza, hepatitis, including hepatitis A, B, C and E, otitis media,rabies, polio, HIV, parainfluenza, rotavirus, Epstein Barr Virus, CMV,chlamydia, non-typeable haemophilus, moraxella catarrhalis, humanpapilloma virus, tuberculosis including BCG, gonorrhoea, asthma,atheroschlerosis malaria, E-coli, Alzheimers, H. Pylori, salmonella,diabetes, cancer, herpes simplex, human papilloma and the like othersubstances including all of the major therapeutics such as agents forthe common cold, Anti-addiction, anti-allergy, anti-emetics,anti-obesity, antiosteoporeteic, anti-infectives, analgesics,anesthetics, anorexics, antiarthritics, antiasthmatic agents,anticonvulsants, anti-depressants, antidiabetic agents, antihistamines,anti-inflammatory agents, antimigraine preparations, antimotion sicknesspreparations, antinauseants, antineoplastics, antiparkinsonism drugs,antipruritics, antipsychotics, antipyretics, anticholinergics,benzodiazepine antagonists, vasodilators, including general, coronary,peripheral and cerebral, bone stimulating agents, central nervous systemstimulants, hormones, hypnotics, immunosuppressives, muscle relaxants,parasympatholytics, parasympathomimetrics, prostaglandins, proteins,peptides, polypeptides and other macromolecules, psychostimulants,sedatives, sexual hypofunction and tranquilizers and major diagnosticssuch as tuberculin and other hypersensitivity agents.

A needle cannula 16 is in fluid communication with an outlet port 18that leads to the reservoir 14. The outlet port 18 allows for thesubstance to be expelled from the prefillable container 12 through areceiver 20 disposed at the end of the prefillable container 12. Theneedle cannula 16 is inserted through a hub portion 22, which is securedto the receiver 20 through a variety of known manners. In one example,an interference fit is provided between the interior of the hub 22 andthe exterior of the receiver 20. In another example, a conventional luerfit arrangement is provided to secure the hub 22 to the end of theprefillable container 12. As can be appreciated, a needle assemblydesigned according to this invention is readily adapted to a widevariety of conventional syringe styles.

Alternatively to affixing the needle cannula 16 to the receiver 20, theneedle cannula 16 can be affixed to the hub 22 prior to attaching thehub 22 to the receiver 20. A limiter 24 surrounds the needle cannula 16and includes a generally flat skin engaging surface 26 extending in aplane generally perpendicular to an axis of the needle cannula 16 withabout fifteen degrees or more preferably with about five degrees. Theskin engaging surface 26 is best seen in FIGS. 4 and 5. The flat skinengaging surface 26 stabilizes the intradermal delivery device duringinjection and thus preferably has a cross-sectional dimension of atleast 5 mm or between 5 and 20 mm. The limiter 24 includes a needleopening 28, which closely receives a forward tip 30 of the needlecannula 16 extending therethrough (FIG. 4). The dimensional relationshipbetween the needle opening 28 and the forward tip 30 can be controlleddepending on the needs of a particular situation. The forward tip 30extends away from the skin engaging surface 26 a distance fromapproximately 0.5 mm to approximately 3 mm. Therefore, the skin engagingsurface 26 limits the depth the needle cannula 16 can penetrate into theskin of the animal. Further, an elastomeric insert or septum 31 may beinserted centrally in the skin engaging surface 26 in which case theneedle cannula 16 pierces the elastomeric surface when attaching thelimiter 24 to the hub 22 (FIG. 3). The elastomeric insert functions asan assembly aid so that the needle cannula 16 does not need to bethreaded through the needle opening 28.

The forward tip 30 includes a beveled edge 32 angled such that thelength of the forward tip 30 is reduced from that of a standardhypodermic needle tip. Preferably, the beveled edge 32 ranges in lengthbetween approximately 0.8 mm and 1.0 mm. More preferably, the bevelededge 32 includes a length of approximately 0.9 mm. A standard beveledtip length ranges from approximately 1.3 mm to 1.6 mm. The reducedlength of the present beveled edge 32 reduces the potential of theneedle cannula 16 passing through the dermis layer of the skin of theanimal and resulting in the substance from the reservoir 14 beinginjected into the subcutaneous region of the animal.

A cap 34 is positioned adjacent the skin engaging surface 26 to coverthe forward tip 30 of the needle cannula 16. Preferably, the cap 34 isformed from an elastomeric material or thermoplastic elastomer thatwould allow the forward tip 30 to penetrate the cap surface and thus besealed by the cap 34. Accordingly, the cap 34, by sealing the needlecannula 16, seals the reservoir 14 preventing the substance from leakingfrom the reservoir 14 through the needle cannula 16 prior toadministering the intradermal injection.

Referring to FIG. 2, an adapter 36 is fixed to a flange 38 disposed onan opposite end of the prefillable container 12 from the receiver 20. Aplurality of snaps 40 clasp the flange 38 to secure the adapter 36 tothe prefillable container 12. The adapter 36 provides an engagementsurface for the prefillable container 12 to be stored in a tray 42 usedfor processing and shipping the intradermal delivery device 10. Aplunger 44 includes an activation flange 46 at one end and a stopper 48at an opposite end as is known in the art. The stopper 48 is slidablydisposed within the reservoir 14 and is selectively actuated to expelthe substance from the reservoir 14 through the needle cannula 16.Therefore, to administer an intradermal injection, the skin engagingsurface 26 of the limiter 24 is pressed against the skin of the animalcausing the needle cannula 16 to penetrate the skin and the activationflange or end 46 on the plunger 44 is depressed to expel the solutionfrom the reservoir 14.

In a preferred embodiment, the limiter 24 functions as an enclosure toconceal or enclose the needle cannula 16 after an intradermal injectionhas been administered. Therefore, as shown in FIG. 4, the limiter 24 islocated in a first position 50 exposing the forward tip 30 enabling anintradermal injection to be administered. FIG. 5 shows the limiterlocated in a second position 52 in which the needle cannula 16 is fullyretracted inside the limiter 24 preventing any further access to theneedle cannula 16 after an intradermal injection has been administered.

Referring now to FIG. 3A, the hub 22 includes at least one lockingfinger 54 and at least one stop 56. Preferably, the limiter 24 includestwo each of the locking finger 54 and the stop 56. Each locking finger54 is cantilevered in a direction opposite the direction of the forwardtip 30. Each stop 56 is cantilevered in a direction that is the same asthe direction of the forward tip 30. Each locking finger 54 includes atab 58, the purpose of which will be described further hereinbelow. Eachlocking finger 54 is attached to the hub 22 proximate to a helical rib60 that centers the hub 22 inside the limiter 24. However, it is notnecessary that the locking fingers 54 be attached to the limiter 24proximate to the helical rib 60, which is only illustrated by way ofexample. The limiter 24 defines at least one slot 62 oriented generallyparallel to the needle cannula 16 in a wall 64 of the limiter 24. Aprotuberance 66 is disposed on one side of the slot 62, the purpose ofwhich will become evident further below.

Each tab 58 is received by the slot 62 when the hub 22 is inserted intothe limiter 24. The protuberance 66 is positioned between each lockingfinger 54 and stop 56 when the limiter 24 is located in the firstposition 50. The tab 58 abuts the protuberance 66 in each slot 62providing enough resistance to the limiter 24 sliding upon the hub 22 toinsert the needle cannula 16 in to the skin of the animal and administerthe intradermal injection. The tabs 58 are snappable over theprotuberance 66 to move the limiter 24 from the first position 50 to thesecond position 52 subsequent to administering the intradermalinjection.

To move the limiter 24 from the first position 50 to the second position52, the prefillable container 12 is pulled away from the limiter 24 asthough trying to separate the prefillable container 12 from the limiter24. Under sufficient separating force, the tabs 58 will snap over theprotuberances 66 allowing the stops 56 to move outwardly from the insideof the limiter 24. A rib 68 circumscribes the inner surface 70 of thelimiter 24 and functions as a catch (FIG. 4). Each tab 58 prevents thehub 22 from being removed from the limiter 24 by engaging a back end ofthe slot 62. Upon passing the rib 68, each stop 56 expands into theinner surface 70 disposed inside the limiter 24 and engage the rib 68thereby preventing the limiter 24 from being moved from the secondposition 52 to the first position 50. Accordingly, the needle cannula 16is secured inside the limiter 24 and cannot be exposed once the limiter24 has been moved to the second position 52.

Referring to FIGS. 2 and 3A, the cap includes an annular shaped ring 74disposed upon a surface that abuts the skin engaging surface 26 of thelimiter 24. The ring is aligned coaxially with the needle cannula 16 andis received within an annular groove 76 disposed within the skinengaging surface 26. In the preferred embodiment, the outer dimension ordiameter of the cap is equal to or less than the receiver 20. The ring74 snaps into the annular groove 76 securing the cap 34 to the limiter24. A tip bulge 77 (FIG. 2) is received by the needle opening 28 in theskin engaging surface 26. The forward tip 30 of the needle cannula 16penetrates the tip bulge 77 sealing the needle cannula 16 and preventingthe substance from leaking out of the reservoir 14 through the needlecannula 16. FIG. 3B shows an alternative skin engaging surface 67 ashaving a plurality of spokes 59 projecting outwardly from the axisformed from the needle cannula 16.

An alternate embodiment is generally shown in FIGS. 6 and 7 at 81. Inthis embodiment, an alternative hub 80 secures an alternative limiter 82in the same fashion as that described in the preferred embodiment. Thealternative limiter 82 is stationary on the alternative hub 80 and isnot moved into a first or second position. A needle plunger 84 isinserted through an alternative limiter wall 86 at an angle generallyperpendicular to the needle cannula 16. The needle plunger 84 isretained in the wall 86 either through a friction fit, or an equivalentthat allows the needle plunger 84 to be forced inwardly of thealternative limiter 82. As shown in FIG. 7, the needle plunger 84functions as the needle cannula enclosure when pushed inwardly of thealternate limiter 82 in which case the needle cannula 16 is bent andtherefore retracted into the limiter 82 preventing exposure to theneedle cannula 16 subsequent to administering an intradermal injection.

Referring to FIG. 8A an alternate assembly 110 adapted to enclose theneedle cannula 16 subsequent to administering an intradermal injectionis shown. A sleeve 112 generally defining a tube slidably circumscribesthe limiter 114. The sleeve 112 includes a skin engaging end 116 that isaligned in generally the same plane as the skin engaging surface 118when the assembly 110 is prepared for administering the intradermalinjection. A rearward end 120 of the sleeve 112 is tapered inwardlytowards the axis of the needle cannula 16. The rearward end 120 abuts arear flange 122 or the limiter 114, which prevents the sleeve 112 frombeing removed from the limiter 114 in the direction of the prefillablecontainer 12. In this embodiment, an elastomeric tip cap 123 isremovably secured to the skin engaging surface 118 and receives theforward tip 30 of the needle cannula 16.

Subsequent to administering the intradermal injection, the sleeve 112may be manually pulled in the direction of the forward tip 30 of theneedle cannula 16 as shown in FIG. 8B. The limiter 114 includes a sleevestop 124, which engages a corresponding contour 126 disposed on aninside surface of the sleeve 112 thereby preventing the sleeve frombeing removed from the limiter 114. At least one ramp 128 is disposedupon an outer surface of the limiter 114 over which the rearward end 120of the sleeve 112 slides when the sleeve 120 is moved to cover theforward tip 30 of the needle cannula 16. The ramp 128 prevents thesleeve 112 from being moved toward the prefillable container 12re-exposing the forward tip 30 once the rearward end 120 of the sleeve112 has been slid past the ramp 128 to enclose the needle cannula 16.

As will now be understood, the intradermal delivery device of thisinvention includes a needle enclosure means which encloses or concealsthe needle cannula tip following injection and which preferably cannotbe retracted to prevent accidental needle contact or reuse. In oneembodiment shown in FIGS. 4 and 5, the limiter 24 may be extendedfollowing injection and locked in place. In a second embodiment shown inFIGS. 6 and 7, the needle cannula 16 is bent or deformed beyond itselastic limit by plunger 82 to permanently enclose the tip portion 30within the limiter 82. In a third embodiment shown in FIGS. 8A and B,the assembly includes an extendable shield 112, which locks in theextended position, preventing contact with the needle. Alternatively,the needle assembly may be retractable as disclosed, for example, in acopending application Ser. No. 09/834,669, filed Apr. 13, 2001 entitled“Prefillable Intradermal Injector,” the disclosure of which isincorporated by reference.

When the hub portion 22 and limiter 24 are attached to the front end ofa prefillable container 12 in the form of a syringe barrel, theassembled device 10 is preferably supplied to the pharmaceuticalindustry in sterile, clean, ready to fill packaging to facilitateprocessing. This processing includes filling and stoppering while thedevice 10 is suspended in a nest (not shown). However, the diameter ofthe limiter 24 is significantly greater than the diameter of the 0.4 mlor 0.5 ml syringe barrel and the barrel flanges, from which the barrelsare normally suspended in the nest. Thus, the nest typically used forthis small barrel size has holes (chimneys) which are too small for thelimiter 24 to pass through, and a nest normally used for a larger barrel(1–3 ml) must be employed.

To prevent the device 10 from falling through this nest, the flanges ofthe syringe barrel must be increased in diameter through the addition ofthe adapter 36. In addition, the chimneys of the nest serve the functionof centering the device below the filling nozzles and stopper insertiontubes on automated filling machines. If the devices 10 are not centeredproperly, the filling nozzle can hit the side of the syringe barrelwhile moving into the barrel at the start of the filling process,resulting in damage to the nozzle, inaccurate fill volumes, potentialglass breakage or particulate contamination when the syringe barrel isformed of glass, or wetting of the barrel inner wall above the areawhich will subsequently be stoppered. This could compromise thesterility seal created between the stopper ribs and barrel wall,compromising sterility. During the stoppering operation, where centeringis even more critical, poor centering can result in damage to thestainless steel insertion tube, glass breakage, or stoppers being placedcrookedly (or not at all) in the barrel, resulting in a poor seal.

With the small diameter syringe barrel placed in the larger than normaldiameter nest chimneys, the chimneys lose their centering function asthe barrels are free to move in a large radius. Therefore, the diameterof the barrel must be built up so that it is only marginally smallerthan the inner diameter of the chimney. This is accomplished by theaddition of the adapter 36, preferably made of plastic, slid on from thetip end of the barrel, before attaching the hub portion 22 and limiter24, or snapped on from the side of the syringe barrel.

To minimize the number of parts to be added to the syringe barrel, theflange extending features required above are incorporated with thediameter increasing features to form one component referred to as theadapter 36 or a barrel spacer.

Several lengths are possible for the adapter 36. A short adapter 36provides the two functions mentioned previously. A longer adapter (notshown) also can serve as a labeling surface, as an alternative toplacing the label directly on the outer diameter of the syringe barrel.The larger diameter adapter permits the use of a larger label andthereby permits information to be incorporated on the label. The upperlimit to the length of the adapter 36 is determined by the volume ofliquid substances placed in the syringe barrel and the length of thestopper. GMPs require that injectable liquid substances be 100%inspected for particulate contamination, and this is conducted eithervisually by operators or using automated vision systems, both of whichrequire an unobstructed, 360 degree view of the liquid substance. Inaddition, the stopper must be inspected for the presence of liquidtrapped between the ribs, potentially compromising sterility. Thus, theadapter 36 must end at a point beyond the back end of the stopper,allowing a clear view of both the liquid substance and the stopper.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims, whereinreference numerals are merely for convenience and are not to be in anyway limiting, the invention may be practiced otherwise than asspecifically described.

1. A delivery device for use in injecting medical substances into theskin of an animal, comprising: a prefillable container adapted forstoring a medical substance; a needle cannula attached to said deliverydevice and having a forward tip extending away from said deliverydevice; a hub portion secured around said needle cannula; a limiterportion surrounding said needle cannula and extending away from said hubportion toward said forward tip of said needle cannula, said limiterportion including a generally flat skin engaging surface extending in aplane generally perpendicular to an axis of said needle cannula andbeing adapted to be received against skin of an animal to administer anintradermal injection of the substance, said forward tip extendingbeyond said skin engaging surface length of approximately 0.5 mm toapproximately 3 mm, wherein said limiter portion limits penetration ofsaid needle cannula into the dermis layer of the skin of the animalthereby injecting substance into the dermis layer of the animal; whereinsaid hub portion defines a locator for said limiter thereby positioningsaid limiter upon said device; and an enclosure means for concealingsaid needle cannula after administering said intradermal injection.
 2. Adevice as set forth in claim 1 wherein said enclosure means comprisessaid limiter, which is slidably disposed upon said hub having at least afirst position and a second position, said first position exposing saidforward tip of said needle cannula and said second position concealingsaid forward tip of said needle cannula.
 3. A device as set forth inclaim 2 wherein said enclosure means comprises a needle plunger insertedthrough said limiter and being depressable for bending said needlecannula beyond its elastic limit thereby retracting said needle cannulainto said limiter.
 4. A device as set forth in claim 3 wherein saidneedle plunger is oriented generally perpendicular to said needlecannula.
 5. A device as set forth in claim 2 wherein said hub portion isattachable to an outlet port of said prefillable container.
 6. A deviceas set forth in claim 2 further including a cap positioned adjacent saidskin engaging surface thereby concealing said forward tip of said needlecannula wherein said cap has an outside dimension equal to or less thansaid limiter.
 7. A device as set forth in claim 6 wherein said capcomprises an elastomeric material.
 8. A device as set forth in claim 6wherein said forward tip of said needle cannula penetrates said capthereby sealing said needle cannula.
 9. A device as set forth in claim 2wherein said limiter includes at least one slot oriented generallyparallel to said needle cannula and having a protuberance disposed onone side thereof.
 10. A device as set forth in claim 9 wherein said hubincludes at least one locking finger and at least one stop, said atleast one locking finger cantilevered away from said forward tip andsaid at least one stop being cantilevered toward said forward tip.
 11. Adevice as set forth in claim 10 wherein said at least one locking fingerincludes a tab received by said slot in said limiter.
 12. A device asset forth in claim 11 wherein said tab is snappable over saidprotuberance for moving said limiter from said first position to saidsecond position.
 13. A device as set forth in claim 12 wherein saidprotuberance is disposed between said tab and said at least one stopwhen said limiter is located in said first position.
 14. A device as setforth in claim 13 wherein said limiter includes a catch engaging said atleast one stop when said limiter is in said second position therebypreventing said limiter from being moved into said first position fromsaid second position.
 15. An intradermal delivery device for injectingsubstances into the skin of an animal, comprising: a prefillablecontainer having a reservoir adapted to contain a selected substance andan outlet port that allows the substance to be expelled from saidreservoir during an injection; a needle cannula in fluid communicationwith said outlet port and having a forward tip adapted to penetrate theskin of an animal; a limiter surrounding said needle and having agenerally flat skin engaging surface extending in a plane generallyperpendicular to an axis of said needle cannula adapted to be placedagainst the skin of the animal to administer an intradermal injection ofthe substance, said needle forward tip extending away from the said skinengaging surface from approximately 0.5 mm to approximately 3 mm suchthat said limiter limits penetration of said forward tip into the dermislayer of the skin of the animal thereby injecting the substance into thedermis layer of the animal; and an enclosure means moveable to concealsaid needle cannula.
 16. The device as set forth in claim 15 whereinsaid prefillable container comprises a syringe having a generallyhollow, cylindrical body portion and a plunger received within saidreservoir, said plunger being selectively movable within said reservoirthereby causing the substance to be forced out of said outlet port whileadministering an intradermal injection.
 17. The device as set forth inclaim 16 including a hub portion supporting said needle cannula andbeing selectively secured to said prefillable container near said outletport.
 18. A device as set forth in claim 17 wherein said enclosure meanscomprises said limiter, which is slidably disposed upon said hub havingat least a first position and a second position, said first positionexposing said forward tip of said needle cannula and said secondposition concealing said forward tip of said needle cannula.
 19. Adevice as set forth in claim 18 wherein said limiter defines at leastone slot oriented generally parallel to said needle cannula and having aprotuberance disposed on one side thereof.
 20. A device as set forth inclaim 19 wherein said hub includes at least one locking finger and atleast one stop, said at least one locking finger cantilevered away fromsaid forward tip and said at least one stop being cantilevered towardsaid forward tip.
 21. A device as set forth in claim 20 wherein said atleast one locking finger includes a tab received by said slot in saidlimiter.
 22. A device as set forth in claim 21 wherein said tab issnappable over said protuberance for moving said limiter from said firstposition to said second position.
 23. A device as set forth in claim 22wherein said protuberance is disposed between said tab and said at leastone stop when said limiter is located in said first position.
 24. Adevice as set forth in claim 23 wherein said limiter includes a catchengaging said at least one stop when said limiter is in said secondposition thereby preventing said limiter from being moved into saidfirst position from said second position.
 25. A device as set forth inclaim 15 wherein said enclosure means comprises a needle plungerinserted through said limiter and being depressable for bending saidneedle cannula thereby retracting said needle cannula into said limiter.26. A device as set forth in claim 25 wherein said needle plunger isoriented generally perpendicular to said needle cannula.
 27. A device asset forth in claim 15 further including a removable cap positionedadjacent said skin engaging surface thereby concealing said forward tipof said needle cannula having an outside dimension equal to or less thansaid limiter.
 28. A device as set forth in claim 27 wherein said capcomprises an elastomeric material.
 29. A device as set forth in claim 28wherein said forward tip of said needle cannula penetrates said capthereby sealing said needle cannula and preventing the substance fromleaking from said reservoir.
 30. A device as set forth in claim 15wherein said hub defines a locator for said limiter thereby positioningsaid limiter upon said assembly.